Crystal structure and Hirshfeld surface analysis of 5-oxo-7-phenyl-2-(phenylamino)-1H-[1,2,4]triazolo[1,5-a]pyridine-6,8-dicarbonitrile dimethyl sulfoxide monosolvate

In the crystal, intermolecular N—H⋯O and C—H⋯O hydrogen bonds connect molecules into chains along the b-axis direction through the dimethyl sulfoxide solvent molecule, forming C(10) (6) motifs. These chains are connected via S—O⋯π interactions, π–π stacking interactions and van der Waals interactions.


Chemical context
Diverse carbon-carbon and carbon-heteroatom bond-formation reactions are considered fundamental tools in organic synthesis. The reaction has also been amplified, extending these methods to different fields of chemistry, as well to the synthesis of natural products, in medicinal and pharmaceutical chemistry, material science, supramolecular chemistry etc (Ç elik et al., 2023;Chalkha et al., 2023;Tapera et al., 2022;Gurbanov et al., 2020;Zubkov et al., 2018). Triazolo [1,5a]pyridines are accessible heterocyclic compounds andsubstituted pyridines are among the most widely used starting materials for their synthesis. The most common synthetic pathways to these compounds are well-reviewed in the literature (Jones & Abarca, 2010;Soliman et al., 2014;Kotovshchikov et al., 2021). The triazolo[1,5-a]pyridine moiety is a widespread structural motif in various synthetic biologically active compounds, possessing cardiovascular, trypanocidal, nitric oxide synthase inhibitor and antimicrobial activity, and in non-hormonal compounds with antifertility activity and leishmanicidal activity (Jones & Abarca, 2010;Mohamed et al., 2013;Poustforoosh et al., 2022).

Figure 2
The molecular structure of the title compound, showing the atom labelling and displacement ellipsoids drawn at the 50% probability level. Table 1 Hydrogen-bond geometry (Å , ). Symmetry code: (i) x þ 1; y þ 1; z.

Figure 3
A view along the c axis of the N-HÁ Á ÁO and C-HÁ Á ÁO bonds in the title compound.
In the crystal of HODQEZ, pairs of N-HÁ Á ÁN hydrogen bonds link the molecules, forming inversion dimers with an R 2 2 (8) ring motif. The dimers are linked by C-HÁ Á Á and C-BrÁ Á Á interactions, forming layers parallel to the bc plane. In the crystal of HODQID, molecules are linked by N-HÁ Á ÁN and C-HÁ Á ÁO hydrogen bonds, forming chains propagating along the b-axis direction. In the crystal of RETCAX, N-HÁ Á ÁN hydrogen bonds link the molecules into supramolecular chains propagating along the c-axis direction.

Synthesis and crystallization
To a solution of 1,6-diamino-2-oxo-4-phenyl-1,2-dihydropyridine-3,5-dicarbonitrile (0.82 g, 5.1 mmol) in DMF (25 mL) was added 10 mL of an aqueous solution of potassium hydroxide (0.28 g, 5.1 mmol). The mixture was stirred at room temperature for 2 h. Then an equimolar amount of phenylisothiocyanate (0.51 g, 5.2 mmol) was added to the vigorously stirred reaction mixture and left overnight. After completion of the reaction, monitored by TLC, the reaction mixture was acidified by adding conc. HCl (4 mL). The precipitated solids were separated by filtration and recrystallized from an ethanol/water (1:1) solution (yield 80%; m.p. 557-558 K). Single crystals were grown from a DMSO solution.   Table 2 Summary of short interatomic contacts (Å ) in the title compound.

Refinement
Crystal data, data collection and structure refinement details are summarized in  SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL (Sheldrick, 2015b); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: PLATON (Spek, 2020).  (Rigaku OD, 2021) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.